Portage, the Funtoo Linux package manager has a command called <code>emerge</code> which is used to build and install packages from source. It also takes care of installing all of the package's dependencies. You call emerge like this:

When you install a package by specifying its name in the command-line, Portage records its name in the /var/lib/portage/world file. It does so because it assumes that, since you have installed it by name, you want to consider it part of your system and want to keep the package updated in the future. This is a handy feature, since when packages are being added to the world set, we can update our entire system by typing:

(chroot) # emerge --sync
(chroot) # emerge -auDN @world

This is the "official" way to update your Funtoo Linux system. Above, we first update our Portage tree using git to grab the latest ebuilds (scripts), and then run an emerge command to update the world set of packages. The options specified tell emerge to:

a - show us what will be emerged, and ask us if we want to proceed

u - update the packages we specify -- don't emerge them again if they are already emerged.

D - Consider the entire dependency tree of packages when looking for updates. In other words, do a deep update.

N - Update any packages that have changed (new) USE settings.

You should also consider passing --with-bdeps=y when emerging @world, at least once in a while. This will update build dependencies as well.

Of course, sometimes we want to install a package but not add it to the world file. This is often done because you only want the package installed temporarily or because you know the package in question is a dependnecy of another package. If this behavior is desired, you call emerge like this: